Peptide specificity analysis of peptide: N-glycanases using synthetic chitobiose-pentapeptides

Background: peptide: n-glycanase is a deglycosylation enzyme releasing n-glycan from glycoproteins. although glycan specificity analysis of this enzyme has been reported,recognition requirements for the peptide sequence have not been precisely elucidated. objective: in this study,we carried out peptide specificity analysis of several peptide:n-glycanases. methods: using synthetic chitobiose-pentapeptide substrates having a systematic series of amino acid sequences composed of hydrophobic leucine and hydrophilic serine,we examined the peptide specificities of peptide: n-glycanases comprising yeast cytoplasmic pngase,bacterial pngase f,and plant pngase a by ultra-performance liquid chromatography combined with electrospray ionization mass spectrometry. results: we found that each of the pngases had higher activity for the more hydrophobic (leucinerich) chitobiose-pentapeptides,although the sensitivities of the pngases for hydrophobicity varied. cytoplasmic pngase showed broad specificity. in contrast,pngase a showed moderate specificity. pngase f showed the highest specificity. conclusion: pngases from different origins had similar but significantly independent peptide specificities. © 2017 bentham science publishers.